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Commit 73583331 authored by Peter Collingbourne's avatar Peter Collingbourne Committed by Gerrit Code Review
Browse files

Merge "Fix scudo MTE tests."

parents fad8eaba 7827991d
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+0 −7
Original line number Diff line number Diff line
@@ -293,13 +293,6 @@ cc_test {
        "libdebuggerd/test/utility_test.cpp",
    ],

    product_variables: {
        malloc_not_svelte: {
            srcs: ["libdebuggerd/test/scudo_test.cpp"],
            header_libs: ["scudo_headers"],
        },
    },

    target: {
        android: {
            srcs: [
+2 −3
Original line number Diff line number Diff line
@@ -34,10 +34,9 @@ class Memory;

class ScudoCrashData {
 public:
  ScudoCrashData() = default;
  ScudoCrashData() = delete;
  ~ScudoCrashData() = default;

  bool SetErrorInfo(unwindstack::Memory* process_memory, const ProcessInfo& process_info);
  ScudoCrashData(unwindstack::Memory* process_memory, const ProcessInfo& process_info);

  bool CrashIsMine() const;

+38 −78
Original line number Diff line number Diff line
@@ -14,11 +14,6 @@
 * limitations under the License.
 */

#include <stdint.h>
#include <unistd.h>

#include <vector>

#include "libdebuggerd/scudo.h"
#include "libdebuggerd/tombstone.h"

@@ -30,92 +25,57 @@

#include "tombstone.pb.h"

bool ScudoCrashData::SetErrorInfo(unwindstack::Memory* process_memory,
std::unique_ptr<char[]> AllocAndReadFully(unwindstack::Memory* process_memory, uint64_t addr,
                                          size_t size) {
  auto buf = std::make_unique<char[]>(size);
  if (!process_memory->ReadFully(addr, buf.get(), size)) {
    return std::unique_ptr<char[]>();
  }
  return buf;
}

ScudoCrashData::ScudoCrashData(unwindstack::Memory* process_memory,
                               const ProcessInfo& process_info) {
  if (!process_info.has_fault_address) {
    return false;
    return;
  }

  std::vector<char> stack_depot(__scudo_get_stack_depot_size());
  if (!process_memory->ReadFully(process_info.scudo_stack_depot, stack_depot.data(),
                                 stack_depot.size())) {
    return false;
  auto stack_depot = AllocAndReadFully(process_memory, process_info.scudo_stack_depot,
                                       __scudo_get_stack_depot_size());
  auto region_info = AllocAndReadFully(process_memory, process_info.scudo_region_info,
                                       __scudo_get_region_info_size());
  auto ring_buffer = AllocAndReadFully(process_memory, process_info.scudo_ring_buffer,
                                       __scudo_get_ring_buffer_size());
  if (!stack_depot || !region_info || !ring_buffer) {
    return;
  }
  std::vector<char> region_info(__scudo_get_region_info_size());
  if (!process_memory->ReadFully(process_info.scudo_region_info, region_info.data(),
                                 region_info.size())) {
    return false;
  }
  std::vector<char> ring_buffer(__scudo_get_ring_buffer_size());
  if (!process_memory->ReadFully(process_info.scudo_ring_buffer, ring_buffer.data(),
                                 ring_buffer.size())) {
    return false;
  }

  uintptr_t page_size = getpagesize();

  untagged_fault_addr_ = process_info.untagged_fault_address;
  uintptr_t fault_page = untagged_fault_addr_ & ~(page_size - 1);
  uintptr_t fault_page = untagged_fault_addr_ & ~(PAGE_SIZE - 1);

  // Attempt to get 16 pages before the fault page and 16 pages after.
  constexpr size_t kExtraPages = 16;
  std::vector<char> memory(page_size * (kExtraPages * 2 + 1));

  // Read faulting page first.
  size_t memory_index = kExtraPages;
  if (!process_memory->ReadFully(fault_page, &memory[memory_index * page_size], page_size)) {
    return false;
  uintptr_t memory_begin = fault_page - PAGE_SIZE * 16;
  if (memory_begin > fault_page) {
    return;
  }

  // Attempt to read the pages after the fault page, stop as soon as we
  // fail to read.
  uintptr_t read_addr = fault_page;
  if (!__builtin_add_overflow(fault_page, page_size, &read_addr)) {
    memory_index++;
    for (size_t i = 0; i < kExtraPages; i++, memory_index++) {
      if (!process_memory->ReadFully(read_addr, &memory[memory_index * page_size], page_size)) {
        break;
  uintptr_t memory_end = fault_page + PAGE_SIZE * 16;
  if (memory_end < fault_page) {
    return;
  }
      if (__builtin_add_overflow(read_addr, page_size, &read_addr)) {
        break;
      }
    }
  }
  uintptr_t memory_end = read_addr;

  // Attempt to read the pages before the fault page, stop as soon as we
  // fail to read.
  memory_index = kExtraPages;
  if (fault_page > 0) {
    read_addr = fault_page - page_size;
    for (size_t i = 0; i < kExtraPages; i++, memory_index--) {
      if (!process_memory->ReadFully(read_addr, &memory[(memory_index - 1) * page_size],
                                     page_size)) {
        break;
  auto memory = std::make_unique<char[]>(memory_end - memory_begin);
  for (auto i = memory_begin; i != memory_end; i += PAGE_SIZE) {
    process_memory->ReadFully(i, memory.get() + i - memory_begin, PAGE_SIZE);
  }
      if (read_addr == 0) {
        memory_index--;
        break;
      }
      read_addr -= page_size;
    }
  }
  size_t start_memory_index = memory_index;
  uintptr_t memory_begin = fault_page - (kExtraPages - memory_index) * page_size;

  std::vector<long> memory_tags((memory_end - memory_begin) / kTagGranuleSize);
  read_addr = memory_begin;
  for (size_t i = 0; i < memory_tags.size(); i++) {
    memory_tags[i] = process_memory->ReadTag(read_addr);
    read_addr += kTagGranuleSize;
  auto memory_tags = std::make_unique<char[]>((memory_end - memory_begin) / kTagGranuleSize);
  for (auto i = memory_begin; i != memory_end; i += kTagGranuleSize) {
    memory_tags[(i - memory_begin) / kTagGranuleSize] = process_memory->ReadTag(i);
  }

  __scudo_get_error_info(
      &error_info_, process_info.maybe_tagged_fault_address, stack_depot.data(), region_info.data(),
      ring_buffer.data(), &memory[start_memory_index * page_size],
      reinterpret_cast<const char*>(memory_tags.data()), memory_begin, memory_end - memory_begin);

  return true;
  __scudo_get_error_info(&error_info_, process_info.maybe_tagged_fault_address, stack_depot.get(),
                         region_info.get(), ring_buffer.get(), memory.get(), memory_tags.get(),
                         memory_begin, memory_end - memory_begin);
}

bool ScudoCrashData::CrashIsMine() const {
+0 −233
Original line number Diff line number Diff line
/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdlib.h>
#include <unistd.h>

#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include "libdebuggerd/scudo.h"
#include "libdebuggerd/types.h"
#include "unwindstack/Memory.h"

#include "log_fake.h"

#include <inttypes.h>

// This needs to match the kExtraPages from ScudoCrashData::SetErrorInfo.
constexpr uint64_t kMaxPages = 16;

class MemoryAlwaysZero : public unwindstack::Memory {
 public:
  MemoryAlwaysZero() = default;
  virtual ~MemoryAlwaysZero() = default;

  size_t Read(uint64_t addr, void* buffer, size_t size) override {
    if (test_unreadable_addrs_.count(addr) != 0) {
      return 0;
    }
    test_read_addrs_.insert(addr);
    memset(buffer, 0, size);
    return size;
  }

  void TestAddUnreadableAddress(uint64_t addr) { test_unreadable_addrs_.insert(addr); }

  void TestClearAddresses() {
    test_read_addrs_.clear();
    test_unreadable_addrs_.clear();
  }

  std::set<uint64_t>& test_read_addrs() { return test_read_addrs_; }

 private:
  std::set<uint64_t> test_unreadable_addrs_;

  std::set<uint64_t> test_read_addrs_;
};

TEST(ScudoTest, no_fault_address) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = false;
  info.untagged_fault_address = 0x5000;
  info.scudo_stack_depot = 0x1000;
  info.scudo_region_info = 0x2000;
  info.scudo_ring_buffer = 0x3000;

  ScudoCrashData crash;
  ASSERT_FALSE(crash.SetErrorInfo(&process_memory, info));

  info.has_fault_address = true;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));
}

TEST(ScudoTest, scudo_data_read_check) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = true;
  info.untagged_fault_address = 0x5000;
  info.scudo_stack_depot = 0x1000;
  info.scudo_region_info = 0x2000;
  info.scudo_ring_buffer = 0x3000;

  ScudoCrashData crash;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));

  // Stack Depot unreadable
  process_memory.TestClearAddresses();
  process_memory.TestAddUnreadableAddress(0x1000);
  ASSERT_FALSE(crash.SetErrorInfo(&process_memory, info));

  // The Region Info doesn't exist for 32 bit.
#if defined(__LP64__)
  // Region Info unreadable
  process_memory.TestClearAddresses();
  process_memory.TestAddUnreadableAddress(0x2000);
  ASSERT_FALSE(crash.SetErrorInfo(&process_memory, info));
#endif

  // Ring Buffer unreadable
  process_memory.TestClearAddresses();
  process_memory.TestAddUnreadableAddress(0x3000);
  ASSERT_FALSE(crash.SetErrorInfo(&process_memory, info));

  // Verify that with all scudo data readable, the error info works.
  process_memory.TestClearAddresses();
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));
}

TEST(ScudoTest, fault_page_unreadable) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = true;
  info.untagged_fault_address = 0x5124;
  info.scudo_stack_depot = 0x1000;
  info.scudo_region_info = 0x2000;
  info.scudo_ring_buffer = 0x3000;

  ScudoCrashData crash;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));

  uint64_t fault_page = info.untagged_fault_address & ~(getpagesize() - 1);
  process_memory.TestAddUnreadableAddress(fault_page);
  ASSERT_FALSE(crash.SetErrorInfo(&process_memory, info));
}

TEST(ScudoTest, pages_before_fault_unreadable) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = true;
  info.untagged_fault_address = 0x15124;
  info.scudo_stack_depot = 0x1000;
  info.scudo_region_info = 0x2000;
  info.scudo_ring_buffer = 0x3000;

  ScudoCrashData crash;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));

  uint64_t page_size = getpagesize();
  uint64_t fault_page = info.untagged_fault_address & ~(page_size - 1);

  std::vector<uint64_t> expected_reads = {0x1000, 0x2000, 0x3000};
  for (size_t i = 0; i <= kMaxPages; i++) {
    expected_reads.emplace_back(fault_page + i * page_size);
  }

  // Loop through and make pages before the fault page unreadable.
  for (size_t i = 1; i <= kMaxPages + 1; i++) {
    process_memory.TestClearAddresses();
    uint64_t unreadable_addr = fault_page - i * page_size;
    SCOPED_TRACE(testing::Message()
                 << "Failed at unreadable address 0x" << std::hex << unreadable_addr);
    process_memory.TestAddUnreadableAddress(unreadable_addr);
    ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));
    ASSERT_THAT(process_memory.test_read_addrs(),
                testing::UnorderedElementsAreArray(expected_reads));
    // Need to add the previous unreadable_addr to the list of expected addresses.
    expected_reads.emplace_back(unreadable_addr);
  }
}

TEST(ScudoTest, pages_after_fault_unreadable) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = true;
  info.untagged_fault_address = 0x15124;
  info.scudo_stack_depot = 0x1000;
  info.scudo_region_info = 0x2000;
  info.scudo_ring_buffer = 0x3000;

  ScudoCrashData crash;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));

  uint64_t page_size = getpagesize();
  uint64_t fault_page = info.untagged_fault_address & ~(page_size - 1);

  std::vector<uint64_t> expected_reads = {0x1000, 0x2000, 0x3000};
  for (size_t i = 0; i <= kMaxPages; i++) {
    expected_reads.emplace_back(fault_page - i * page_size);
  }

  // Loop through and make pages after the fault page unreadable.
  for (size_t i = 1; i <= kMaxPages + 1; i++) {
    process_memory.TestClearAddresses();
    uint64_t unreadable_addr = fault_page + i * page_size;
    SCOPED_TRACE(testing::Message()
                 << "Failed at unreadable address 0x" << std::hex << unreadable_addr);
    process_memory.TestAddUnreadableAddress(unreadable_addr);
    ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));
    ASSERT_THAT(process_memory.test_read_addrs(),
                testing::UnorderedElementsAreArray(expected_reads));
    // Need to add the previous unreadable_addr to the list of expected addresses.
    expected_reads.emplace_back(unreadable_addr);
  }
}

// Make sure that if the fault address is low, you won't underflow.
TEST(ScudoTest, fault_address_low) {
  MemoryAlwaysZero process_memory;
  ProcessInfo info;
  info.has_fault_address = true;
  info.scudo_stack_depot = 0x21000;
  info.scudo_region_info = 0x22000;
  info.scudo_ring_buffer = 0x23000;

  ScudoCrashData crash;
  ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));

  uint64_t page_size = getpagesize();
  for (size_t i = 0; i < kMaxPages + 1; i++) {
    process_memory.TestClearAddresses();
    info.untagged_fault_address = 0x124 + i * getpagesize();
    SCOPED_TRACE(testing::Message()
                 << "Failed with fault address 0x" << std::hex << info.untagged_fault_address);
    ASSERT_TRUE(crash.SetErrorInfo(&process_memory, info));
    std::vector<uint64_t> expected_reads = {0x21000, 0x22000, 0x23000};
    uint64_t fault_page = info.untagged_fault_address & ~(page_size - 1);
    expected_reads.emplace_back(fault_page);
    for (size_t j = 1; j <= kMaxPages; j++) {
      expected_reads.emplace_back(fault_page + j * page_size);
    }
    while (fault_page != 0) {
      fault_page -= page_size;
      expected_reads.emplace_back(fault_page);
    }
    ASSERT_THAT(process_memory.test_read_addrs(),
                testing::UnorderedElementsAreArray(expected_reads));
  }
}
+2 −3
Original line number Diff line number Diff line
@@ -193,9 +193,8 @@ void set_human_readable_cause(Cause* cause, uint64_t fault_addr) {
static void dump_probable_cause(Tombstone* tombstone, unwindstack::AndroidUnwinder* unwinder,
                                const ProcessInfo& process_info, const ThreadInfo& main_thread) {
#if defined(USE_SCUDO)
  ScudoCrashData scudo_crash_data;
  if (scudo_crash_data.SetErrorInfo(unwinder->GetProcessMemory().get(), process_info) &&
      scudo_crash_data.CrashIsMine()) {
  ScudoCrashData scudo_crash_data(unwinder->GetProcessMemory().get(), process_info);
  if (scudo_crash_data.CrashIsMine()) {
    scudo_crash_data.AddCauseProtos(tombstone, unwinder);
    return;
  }